Electrical transformer-containing case



Se t. 3 192 1,642,471

p 1 7 c. M. WELCH ELECTRICAL TRANSFORMER CONTAINING CASE Filed Oct. 24. 1921 2 Sheets-Sheet 1 mzzm T i i L "0" .0: 5 u R// L r 2 Q n m WI (LAVA,

ul l l i l l l i u l l ic l l w l' "U" "H II l l l l l m K 1,642,471 p 13, 1927- c. M. WELCH ELECTRICAL TRANSFORMER CONTAINING CASE Fild Oct. 24. 1921 2 Sheets$heet 2 INVENTOR Patented Sept. 13, 1927.

UNITED STATES PATENT OFFICE.

CHARLES M. WELCH, OF OGDEN,- ARKANSAS.

ELECTRICAL SFORMER-CQNTAINING CASE.

Application filed ,OctObCI 24, 1921. seri rm. 510,1 9.

The object of my invention is as ifollow's: (A) To secure the abolishment of using cast iron cases in distribution service transformers with an all sheetinetalneontaming case, convenient to make up inyarious forms and dimensions to suit conventional core and coil designs, with simple partsfeasily'.

constructed in any first class 'sheetinetal shop without the use of expensive forming i dies or much other special machinery.

(B) To secure a substantial; all sheetmetal containing case as above, of various forms and dimensions, which may be readily adapted as a replacement case for any make, style adaptable to my improvement in .transformers, described and claimed in my application Number 495,522 filed Aug. 26, 1921,,

protected whereby the transformer is against water in the oil through a simple inexpensive means. i 1

(D) To-secure an automaticsafety-valve arrangement on all distribution transform-- ers using these cases, whereb excess-pres. sure inside the case is relieve with thearrangement operating to extinguish combustion of the oil in case of fire arising from any temporary electrical disturbances'within the case.

(E) To secure convenient outlets to the supply and service connections.

I attain the object by the arrangementillustrated in the accompanying drawingsin which:

Fig. 1, is a vertical section, showing detail assembly of the essential parts.

Fig. 2, is a top view, with'the cover removed, showing the arrangement of-the terminals and the supporting element adjacent the top.

Fig. 3, is a back view, showing the hangers and rear terminals and the general outline with the cover on the casing.

Fig. 4, is a horizontal section on XY taken in Fig. 3, and illustrates the arrangement of the parts adjacent the bottom of the case, and also shows a novel form of core and coil used in the assembly. The type of core and coil shown is otherwise shown and claimed in my applications for, electrical transformer, Number 510170 filed Oct. 24, 1921. and. electrical transformer core or magnetic circuit, Number 510168 filed Oct. 24, 1921.

Fig. 5, is i horizontal section on X-Y illustrating a conventional multiple magnet e circuit transformer in the case.

Fig.6, is a horizontal section on X-Y illustrating 'a conventional core type magnetic circuit transformer. in the case.

Fig ms a'h'or'izontal section on X--Y ii lusti'ating a' conventional shell type .trans former in. the ,case.

vThese drawingsllustrate, vin connection with the description and the claims, the novel.

features of the sheet metalcasing, the band ing strip ,aro ind. .th,e top of. the casing, the

terminal p'oc'kets' lf ormed" by. the banding strip, the allsheet metal cover, cover holding arrangement, horizontal holding-bolts,

transformer supporting ,means, centering means, movable element comprising safety valve arrangement, limitation by the cover holding bolts of theup and down movement ,of the inovableele nent, supporting and sus pension members cooperating with the cover 7 in the use of the same holding bolts for suspending the transformer from the cover and also holding the cover on thecasing, a transformer suspended from the cover having leadssecuredto the case, andother details contributing to the success of the combination claimed. Siinilar letters refer to similar parts throughout the several views in which: v

The case body A is formed of sheet metal with welded seams for holding the fluid. The banding strip E is also formed of sheet metal and is placed around the top of the case body A in such fashion that offset portions forms the terminal pocket walls which terminal pockets are shown F, G, H. The cover G is made of sheet metal'formed to fit 'the contours of the banding strip with an extension lip C forming a convenient overhang with free clearance between the lip C and the banding strip E.

The supporting ring B adjacent the top of the case, suspends the transformer in the fluid. This ring B is attached to one end of the suspension pieces M. The other end of the suspension pieces M are fastened to the intermediate suspension ring B The intermediate suspension ring B is fastened to the top of the transformer angle iron core clamps J. The bottom of the angle iron core clamps J are fastened to a centering ring N. The core clamps J hold the transformer in position through the medium of the compression bolts L which clamp the pression bolts extended, beyond the face of the core and coil tnitj'in conventional way. The pieces IV shown in section are wood blocks used in connection with" clamping the core shown in proper alignment. Theforegoing described rin'gj'B, pieces M,tringI'B,'

constitute a supportingmember for theelements consisting of the transformer unit T I havinga core'K'and which said supporting,

member comprising'the' foregoing? with attached parts and'the elementunit's will be' "'he reinafter further described" and referred -"to'as the movable.member.-

. Between the portions of'the top edges of the banding strip and'the casebody A and the horizontal flange of the cover'C restin Fig. 2', indicates the bolt'spacing'of the bolts upon them is placed a. felt gasket D- filled with insulating'gum. Conveniently located around the overhanging lip C of'the cover C the horizontalholding'bolts I fornr a detachable means of fastening the cover" on the casing. The reference character I in I shown in Fig. 1. The holding bolts I are arranged in horizontal fashion' and pass 1 with free clearance through holes drilled in the cover extension lip C thence through slotted holes in the banding strip and the case body wall and they are detachably fastened to the supporting ring B. The ring B and the cover C with attached parts are held relatively fixed by the boltsI which can move up or down in the slots in the easing by application of force to any attached part. The up and down movement of the transformer, suspended as described from the cover is regulated or limited by the bolts I acting as stop pins bearing against the cover and the case, whereby the extremities of the slotted holes are varied relative to the location of the said bolts. My invention is notlimited to only the same set of bolts for holding the cover and suspending the transformer as it is obvious certain advantages of my invention may be secured by suspending the transformer directly from the cover in conventional way and fastening the cover by other means consisting of bolts secured to the casing and forming stop or limiting pins against an up and down movement of the cover and suspended transformer. although this may be at the sacrifice of bringing the leads through the case, and by the words or term detachable holding bolts acting as stop pins bearing against 'wall.

Openings 0 are cut ,in the case walls adall suehconstr'uctions are obviously included. The various parts comprising the movable' meinber -are proportioned to secure a sliding fit as it is necessary to slide the prin- -cipal"-part-s' into-the casing in assembly and jacent the terminal pockets through which openings the terminals P are carried to the supply and service-lines through insulator bushingspQ, or conduit-pipe fitting Q, secured in the pocketsof the case; Low voltage transformer-terminals are 'frequently of a lural'number'and I- ins'ulate them Separate-' y and as a unit in adequate strength to pass through'the conduit fitting Q, when'I prefer to'luse-the'conduitpipe connection.

. Hanger lugs R are spotwelded to the case body with the top lug also bolted to the banding strip. These hanger lugs are-bolted' to the hanger'hooks S.

The casing has adjacentthe bottom a valve'or pipe plug -Y for drainingwatery fluid from the isolatingch-amber orcompartment which :is formed by placing a=.fun- -nel shaped baflleV having an: opening-XV in the lower part of the casing in such-fashion that, any water-in the #oil'settling by gravity to the funnel shaped bafile V willdrain throng? the opening W- into the compartment where it is. prevented from circulating into the main body of insulating fluid around the transformer.

Insulating fluid may be placed in. the casing by removing a pipe plug Z in the cover C, and a-valve or pipe plug forming a fluid level vent 8 indicates by. overflow when a suflicientamount of fluid is'inthe casing. The normal fluid level -isindicated by the words fluid level in the drawings. This novel construction renders it-possible to install the transformer without removing the cover for any reason. Thus I prevent the entrance of moisture by removal of the cover in damp weather. My construction throughout supersedes and renders the removable cover without utility. In practice the cover may be secured by the bolts I being placed on under seal thereby insuring a definite guarantee period for the maker.

A suitable name plate #9 of stamped material for approved identification characteristics is secured to the banding strip. The lifting ring U is welded in the cover near the center point of gravity which serves to hold the transformer in a vertical position when being raised to the pole cross arms.

Figures 5, 6, 7, illustrate how readily my containing cases may be used to contain various type conventional transformers. In this connection, the core clamping pieces are out longer or shorter or are varied in number and shape to accommodate the type trans- -said frame, whereby any coventional core clamping arrangement may be employed with the invention.

In the embodiment of the invention with conventional core clamps 'itis obvious changes may be desirable and 'necessain the form and extent and numiber of t e supporting and suspension members herein described, and when such modified construction comes within the scope of my invention as set forth in my claims attached to and forming a part of this specification I do not restrict myself, hereunder, to the exact construction shown in the drawany transformers of obsolete case design, now in service, require new cases by y reason of leaking oil, dry type, broken pi rts,

unsymmetrical case design, small dangerous terminal pockets and insulators and crowding in the case with high temperatures, and moreover, the need of a standardized case construction embodying more safety appliances on small transformers, both from service and manufacturing standpoint, indicates my improvement is useful in the art.

I have shown a polygonal cross section case form in the drawin s which I have found in the octagon and hexagon shapes secures spacious terminal pockets with the banding strip adjacent sides of the case and provides a general symmetrical arrangement. But it can readily be seen my invention may be employed in the circular form of case or in irregular figures, and while the described and illustrated construction is the best means known to me at this time for carrying the invention into effect, I do not wish to be restricted in my claims, hereunder, in the choice of material construction except as comes within the scope of my said claims.

In the present invention an automatic safety valve arrangement is secured in the casing in a novel way. A gasket rests between the horizontal flange of the cover and the top of the casing. The Supporting means B carries the transformer elements herein described comprising the movable member. The holding bolts I detachably fastened to the supporting means and connected through slotted holes in the casing to the lip of the cover thereby join the valve parts which operate in the following way. The movable member and the cover are held relatively fixed by the bolts I which can move up or down in the slots in the casing and move within the limits of the extremities of the slot-ted holes relative to the location of the bolts, whereby the weight of the suspended transformer pulls down in the case until the cover rests tightly on the gasket union between the case and cover. The cover can move from its tight fitting position by force of increase of pressure within the casing occuring on excessive expansion of the fluid under high heat or internal pressure from disruptive electrical discharges within the casing. Thus providing an automatic safety valve arrangement, whereby the transformer and easing provides the valve parts and the weight of the suspended transformer secures an effective valve tension. Difference in weight in transformers is offset by difference in surface area of the covers for different ratings so that the designs can be arranged to provide approximately a similar relation between the weight and the area and insure a dependable action of the valve arrangement. A large factor of safety exists between the pressure sufficient to raise the cover and a pressure great enough to burst the case, therefore I overcome with this arrangement one of the objections to sheet metal cases in practice that internal pressure may burst the case or spring the joints sufliciently to cause them to leak oil. On occurence of fire about the surface of the oil the drawing down of the cover after the pressure is relieved naturally cuts off the supply of oxygen to the fire and stops the combustion.

What I claim is:

1. In combination, a containing case having an opening formed at its upper end, a cover for closing said opening, a transformer within the containing case comprising a core clamped together, a supporting member for the transformer in the upper part of the casing, a means for securing the said core clamping means to the said supporting member forming a suspension frame for securing the said transformer in the said case, a detachable holding means extending through portions of the cover and the case and engaging the said frame cooperating with the said cover for suspending the transformer therefrom and securing the said cover on the said case, and terminal conductors for the transformer passing through the case.

2. The combination with a fluid insulated electrical transformer of a casing with a cover, a gasket between the casing and the cover, enlarged holes in the walls of the easing, a means by which the transformer is supported inside the casing, and a series of bolts engaging portions of the cover which said bolts pass through the said enlarged holes in the said walls of the casing and with the said bolts detachably fastened to the said means by which the transformer is supported inside the casing.

3. In combination, a containing case having an opening formed at its upper end, a. cover for closing said opening, a transformer between ,-the,; cover I and; i he ea-s61 i P Q d zlgygonal iI 1-.cross;s eotion having an opening d6 ,formed at one-end, ;a,.polygona1; cover for d in said ip ning;a d; a egs 'r p ina fl ge'foizm g a etmi i p kets dj .-6,f the eontaining case ;a transformer -wi'thi r-thepgntaining ease oomprisin a core damp tog ther, asunp iu e 1 for thee-t s men-iin: eaupp rpm f the fe ing; a. ma sio ewrins-lhe aid c gclamping means to the supporting member for securingithesaidtransfOrmer in the said case, a detachable holdingmeans extending through the depending flange and the casing and engaging the said supporting member, and terminal eonductors'for-the transformer passing through .the said formed .pockets .w-adjacent Sides; of ,th e ease 5. v- 'lrhe. combination with. a fluid insulated self cooled eleetric'al transf -ormer, a casing therefor, a cover for the oasing a gasket between; the-louver: and the casing, a cover ex- Itension fiorming; a lip do wn ,oyenthe casing,

a series; of, ;bolt s'around.-,theg said of. the eover. and ,detachably, fastened -.through the -case wal ls, a ,s,up orting'means inside the .easing firomlwhicii the transformer is suspendedin the fluid withthe said means detaehabl :tastenedinsliding fitrelation to thesaidlcasing andinfixed relation fit to the saideover, av oenteringmeans in the easing a means forinlethof fluid-through the cover, ai.me ans toroutlet of fluid through the casing, and a fluid levelvent provided ata point near the normal fluid leveL 6. .The combination .with a fluid insulated self cooledelectrical transformer, acasing therefor, 21 cover for the casing, a gasket between .the casing and the cover, a cover extension forming a. lip down over the casing, a supporting means from which the trans former is suspended in the fluid with the said means detachably fastened. in sliding fit relation to the casing and in fixed relation fit tothe cover, a series of bolts around the said lip .of. the cover and detachably fastened through the ease walls tothe said supporting means inside the casing, a plurality of transformer terminal leads through the casing, a centering means in the casing, a means for inlet of fluid-through the cover, a means for outlet of fluid through the casing, 21 fluid level vent providedat a point near the norcover, aseries of boltsarouird tlr vi t c v n te h h yae-ta.te ss fi t ug t e-m e theiseiimm st ing 'means inside the; casing ,Qf

transformer leads through the; terin'g meausinthe easing, frame s e p w Qtt e ttansi memad s c-e cured to the supporting means, a means jp r inlet of fluid through.the coveig, aJiiEanS for outlet of fluid. through fluid level vent provided at apointneadthe normal fluid leveh-and. ajconduitlterminal w entrance comprising a pipe secured to the casing with insulated portions pro'teotingthe terminals. V m :53;

8. In a transformer;- contaihing,. -oase,, a case. body comprising polygonal sides ,an hai'iding strip adjacent the top ot the said case bod a plurality otterminahpockets forn'ied etween portions t of the .banding strip and sides of the said case body and a .cover for the containingease said eolver loo having an overhanging lip .fo hl edqin outline to follow the-plane of thecasing sides v without pockets. whereby. the OdgQS g-Of ,the cover show in outline substantially straight lines meeting in a plurality of anglelforma- .=.105 tion around the casing. z r

9. A safety valve for transformers comprising in combination, a case h0ldi1 1g. insulating fluid, a valve head ,formed -bygthe cover for the case, a. valvetensionsecured 7110 by the weight of a transformer suspended from the said cover in the saidfluid, a valve. seat. at the union of a gasket:between the said case and the said cover.;

10. A pressure operated safety valve fori'115 transformers comprising .in combination, a case holding insulating fluid, a valve head formed by the cover for the case, a valve stem provided in a transformer. suspended in the said fluid in the said case from the 1120 said cover and having port-ions adapted to telescope with portions of the said ease a valve tension provided by the weight. of the said suspended transformer, a valve, seat formed at the union of a z;

siict between the: said cover and the. said case, andqvitlnthe valve opening limited by a detachable holding 1: ans for securing the said-cover ont-he said owe the said means engaging the said cover and the said case being'adapted to provide an up and down movement of the said cover on the said case.

11. In combination, a containing ca'se polygonal in cross section having an opening formed at one end, a polygonal cover for closing said opening and having a depending flange forming terminal pockets with sides of the containing case, a transformer within the containing case comprising a core clamped together, and terminal conductors for the transformer passing through the said formed pockets adjacent sides of the case.

12. In a transformer containing case, a case body comprising polygonal sides, a banding strip adjacent the top of the said case body, a plurality of terminal pockets formed between portions of the said banding strip and sides of the said case body, and

a cover for the containing case the said cover having an overhanging lip extending down on the said pockets and the said sides without pockets.

13. In combination, a containing case having an opening formed at its upper end, a. cover for closing said opening, a trans former Within the containing case comprising a core clamped together and suspended from the cover, portions of the said case and the said cover having surfaces adapted for a movement secured up or down of the said cover with suspended transformer, and detachable holding bolts for the cover acting as stop pins bearing against the said case and the said cover whereby the said movement is limited.

In testimony I afiix my signature.

CHARLES M. WELCH. 

